Fuel composition of diesel fuel

ABSTRACT

The invention relates to a fuel composition based on a diesel fraction, having a sulphur content of less than 10 mg/kg with the boiling range of 180-360° C., characterized in that said fuel composition contains organic peroxides as ignition promoters, which are selected from the group: di-tert-butyl peroxide, 1,1-di-(tert-butylperoxy)cyclohexane, dicumyl peroxide, tert-butyl cumyl peroxide, isobutyl cumyl peroxide, n-butyl cumyl peroxide, isopropyl cumyl peroxide, ethyl cumyl peroxide and methyl cumyl peroxide, and contains an anti-wear additive based on carboxylic acids having the following ratio of components, wt %: 0.01-0.5 organic peroxide, 0.005-0.1 anti-wear additive, and up to 100 being the diesel fraction. The proposed diesel fuel composition allows producing diesel fuel which meets quality performance requirements.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of US national stage patentapplication Ser. No. 17/290,424 filed on Apr. 30, 2021, under 35 U.S.C.§ 371, of International Patent Application No. PCT/RU2020/000021, filedJan. 17, 2020, which claims priority to Russian Patent Application2019112856, filed Apr. 26, 2019 and Russian Patent Application2019101618, filed Jan. 22, 2019, which are incorporated herein byreference in their entirety.

TECHNICAL FIELD

The invention relates to petroleum refining and petrochemistry, namely,to a diesel fuel composition.

BACKGROUND

Diesel fuel remains the most highly-demanded petroleum product both inthe worldwide and in the Russian markets. It is mostly consumed byrailway, water and road freight transportation, as well as by variouselectric generators, military and agricultural equipment.

Modern diesel fuel is a deeply hydroprocessed product having variousadditives, which provide the required environmental and operationalproperties.

A very important quality in the parameters of diesel fuel thatcharacterizes its volatility is the cetane number, and its optimal valueprovides good starting properties of fuel, as well as a lesser amount ofnoxious emissions along with exhaust gases.

In order to enhance the ignition of diesel fuels, ignition promoters areused. Nowadays, additives based on 2-ethylhexyl nitrate are used as theignition promoters in Russia. However, along with advantages,2-ethylhexyl nitrate has a number of disadvantages: it isexplosion-dangerous, may decompose upon explosion, accelerates the fueloxidation, comprises nitrogen, corrosive relative to metals, anddeteriorates antiwear properties of diesel fuel. It is known that inpresence of the ignition promoter based on 2-ethylhexyl nitrate, theconcentration of the antiwear additive must be increased in order toachieve the required fuel lubricity. Also, investigators note that thecetane numbers of diesel fuels are reduced in the process of theirstorage, which is explained by decomposition (by hydrolysis) of2-ethylhexyl nitrate in the presence of water.

Abroad in view of the limitation of the nitrogen content in diesel fuel,the California Air Resources Board (CARB) implies a successivetransition to output of diesel fuels with peroxides.

An additive for a low-sulfur diesel fuel is known in order to reduce thefuel consumption in a diesel engine, characterized in that it comprisesperoxide in the amount of from 0.001 wt. % to 10 wt. %.

(Application WO 2016/174176 A1, 2016).

The additive disadvantage lies in an insufficient efficiency in terms ofincrease of lubricity the diesel fuel lubricity that does not allow theenhancement of this parameter up to the standard requirements.

(U.S. Pat. No. 5,314,511, 1994).

The composition disadvantage lies in a high sulfur content in the fuelcomposition being up to 500 mg/kg of sulfur, while nowadays, moderndiesel fuels comprise up to 10 mg/kg of sulfur. When testing theobtained samples of the fuel composition, an influence of the additiveonto the fuel consumption was studied and a toxicity of emissions wasevaluated, i.e. environmental properties were evaluated, rather thanoperational ones.

The closest analogue of the suggested fuel composition is a diesel fuelformulation comprising an additive of premixed cyclohexyl nitrate or2-ethylhexyl nitrate and peroxides selected from a group of:ditert-butyl peroxide, dicumyl peroxide, cumyl hydroperoxide under amass ratio of said components from 3:1 to 1:3 in the amount of theadditive of 0.1-0.5 wt. %.

(RU Patent No. 2451718, 2012).

This composition disadvantage lies in a presence of the diesel fuelproduced according to the GOST 305-82 that is characterized by anincreased content of sulfuric compounds (up to 0.05 wt. %). Such dieselfuels have good lubricating properties and do not require adding ofantiwear additives. Also, this fuel is produced to supply according tothe state defense order only and for export. Also, the formulation ofthis fuel composition comprises nitrates that does not allow reductionof the content of nitrogen oxides in exhaust gases to the minimum.

SUMMARY

In one aspect of the invention, a fuel composition is provided, wherethe fuel composition based on a diesel fraction having a sulfur contentof less than 10 mg/kg with boiling points in the range of 180-360° C.,characterized in that it comprises ignition promoters such as organicperoxides selected from a group of: di-tert-butyl peroxide,1,1-di(tert-butyl peroxy)cyclohexane, dicumyl peroxide, and an antiwearadditive based on carboxylic acids having the following ratio ofcomponents, wt. %:

-   -   organic peroxide from 0.01 to 0.5,    -   antiwear additive from 0.005 to 0.1, diesel fraction up to 100.

In another aspect of the invention, a fuel composition is provided wherethe fuel composition is based on a diesel fraction having a sulfurcontent of less than 10 mg/kg with boiling points in the range of180-360° C., characterized in that it comprises ignition promoters suchas organic peroxides selected from a group of: tert-butyl cumylperoxide, isobutyl cumyl peroxide, n-butyl cumyl peroxide, and anantiwear additive based on carboxylic acids having the following ratioof components, wt. %:

-   -   organic peroxide from 0.01 to 0.5,    -   antiwear additive from 0.005 to 0.1,    -   fraction up to 100.

In another aspect of the invention, a fuel composition is provided wherethe fuel composition is based on a diesel fraction having a sulfurcontent of less than 10 mg/kg with boiling points in the range of180-360° C., characterized in that it comprises ignition promoters suchas organic peroxides selected from a group of: isopropyl cumyl peroxide,ethyl cumyl peroxide, methyl cumyl peroxide, and an antiwear additivebased on carboxylic acids having the following ratio of components, wt.%:

-   -   organic peroxide from 0.01 to 0.5,    -   antiwear additive from 0.005 to 0.1    -   diesel fraction up to 100.

DETAILED DESCRIPTION

A task of the invention is to create a fuel composition of a low-sulfurdiesel fuel using organic peroxides as ignition promoters that couldmeet the requirements of GOST 32511-2013, GOST R 52368-2005, EN 590,GOST R 55475-2013, TR CU 013/2011.

The posed task is solved by the proposed diesel fuel compositionincluding a diesel fraction with a sulfur content of less than 10 mg/kgwith boiling points in the range of 180-360° C., characterized in thatit comprises a synergistic combination of an organic peroxide as anignition promoter (up to 0.5 wt. %) and an antiwear additive based oncarboxylic acids (up to 0.1 wt. %).

In order to prepare a basic diesel fuel, the following components areused: ultra-low-sulfur (having the sulfur content of less than 10mg/kg)=hydroprocessed diesel fraction and/or a hydrocracking dieselfraction with boiling points in the range of 180-360° C.

The proposed diesel fuel is prepared using a standard equipment bymixing components and additives until a homogeneous product is obtained.

Characteristics of the diesel fuel components, which are used inexamples to support the proposed invention, are shown in Table 1.

As examples of the proposed invention, the diesel fuel compositions wereprepared, with their test results stated in Tables 2, 3 and 4, whereinresults of testing the diesel fuel comprising 2-ethylhexyl nitrate asthe ignition promoter are provided for comparison.

The test results show that the diesel fuel samples comprising organicperoxide as the ignition promoter are highly competitive, in terms of anincrement of the cetane numbers, with diesel fuels comprising2-ethylhexyl nitrate as the ignition promoter.

The combination of the additives' package in the formulation of thediesel fuel, where the package comprises an organic peroxide and theantiwear additive based on carboxylic acids, has a synergistic effect interms of the lubricity of the fuel. Table 2 states experimental valuesof the corrected wear scar diameter according to the HFRR method foreach diesel fuel sample. For comparison, the tables also state dataregarding the lubricity of the diesel fuel samples, which comprise2-ethylhexyl nitrate as an ignition promoter, while the formulation andconcentration of the antiwear additive remain unchanged. Unexpectedly,it has been found that the peroxide additive in the package with theantiwear additive based on carboxylic acids does not negatively affectthe lubricity of the diesel fuel as opposed to 2-ethylhexyl nitrate. Thedistinctive feature of the invention is the synergistic effect that isobserved in case of the combined use of the organic peroxides asignition promoters and the antiwear additive based on carboxylic acidsin the diesel fuel (having the sulfur content of less than 10 mg/kg).

It is known that 2-ethylhexyl nitrate facilitates formation of resinouscompounds in diesel fuels and acceleration of the fuel oxidation. Theobtained data (Table 2) allow to conclude that the ignition promotersbased on organic peroxides have less impact onto formation of a residue.This is advantageous as compared to the ignition promoters based on2-ethylhexyl nitrate. The number of adsorption resins in fuelscomprising ignition promoters based on organic peroxides and2-ethylhexyl nitrate are commensurable and fall within limits of themethod reproducibility.

The effective combination of the ignition promoters based on organicperoxides and the antiwear additive based on carboxylic acids may allowto reduce the concentration of the latter one. This is an advantage ascompared to the ignition promoters based on 2-ethylhexyl nitrate, which,when they are used, make it necessary to increase the concentration ofthe antiwear additive in order to achieve the required lubricity.

Therefore, the proposed diesel fuel composition allows to produce thediesel fuel that meets the requirements of GOST 32511-2013, GOST R52368-2005, EN 590, GOST R 55475-2013 and TR CU 013/2011 in terms ofquality parameters.

TABLE 1 Main characteristics of the diesel fuel componentsHydroprocessed Hydrocracking Parameter diesel fraction diesel fractionCetane number, un. 46.2 55.7 Lubricity: the corrected parameter of 564635 the wear scar diameter at 60° C., μm Fractional formulation: 9.5 1.1distilled up to 180° C., vol. % distilled up to 360° C., vol. % 97.498.3 Overall sulfur content, mg/kg <10 5.1

Tables 2, 3, 4-The component formulation of the samples of the proposeddiesel fuel composition comprising the synergistic composition of theorganic peroxide and the antiwear additive based on carboxylic acids,and results of its testing in comparison with the composition comprising2-ethylhexyl nitrate.

TABLE 2 Content of the components, wt. %/number of sample/ Component 1 22a 2b 3 3a 4 4a 4b 5 Hydroprocessed 99.97 99.77 99.47 99.5 99.77 99.799.77 99.77 99.47 99.77 diesel fraction Hydrocracking diesel fractionAntiwear additive 0.03 0.03 0.03 — 0.03 0.1 0.005 0.03 0.03 0.03Di-tert-butyl — 0.2 0.5 0.5 — — — — — — peroxide 1,1-di — — — — 0.2 0.2— — — — (tert-butyl peroxy)cyclohexane Dicumyl peroxide — — — — — — 0.010.2 0.3 — 2-ethylhexyl nitrate — — — — — — — — — 0.2 Parameter Parametervalue Lubricity: the 398 356 328 359 359 332 425 348 325 405 correctedparameter of the wear scar diameter at 60° C., μm Cetane number, 46.252.0 54.6 54.6 53.3 53.3 51.4 54.8 53.2 

  53.2 in 

  Content of adsorption — 692 765 698 805 867 769 785 803 744 resine, mgper 100 cm² of the fuel Overall residue mass, — 0.300 0.400 0.375 0.6750.725 0.725 0.700 0.675 0.750 ml/106 ml ²⁾ Requirements of GOST 32511-2013, GOST R Content of the components, wt. %/number of sample/52368-2005 and Component 6 7 8 8a 8 10 TR CU 013/2011 Hydroprocesseddiesel fraction Hydrocracking 99.97 99.77 99.77 99.7 99.77 99.77 dieselfraction Antiwear additive 0.03 0.03 0.03 0.1 0.03 0.03 Di-tert-butyl —0.2 — — — — peroxide 1,1-di — — 0.2 0.2 — — (tert-butylperoxy)cyclohexane Dicumyl peroxide — — — — 0.2 — 2-ethylhexyl nitrate —— — — — 0.2 Parameter Parameter value Lubricity: the 404 438 354 337 380467 not more than 460 corrected parameter of the wear scar diameter at60° C., μm Cetane number, 55.7 64.7 62.2 62.2 63.2 62.2 not less than 51in 

  Content of adsorption — 333 263 328 236 116 not more than 2500 ¹⁾resine, mg per 100 cm² of the fuel Overall residue mass, — 0.450 0.5500.650 0.575 0.625 not more than 2 ml/106 ml ²⁾ Note: ¹⁾ Determinedaccording to STO 11605031-056, the regulation is established within theMCO (MKO), ²⁾ Determined according to STO 11605031-077-2013, the methodis qualified, it is not included into the ND for diesel fuel

indicates data missing or illegible when filed

TABLE 3 Content of the components, wt. %/number of sample/ Component 1 22a 2b 3 3a 4 4a 4b 5 Hydroprocessed 99.97 99.77 99.47 99.5 99.77 99.799.77 99.77 99.47 99.77 diesel fraction Hydrocracking diesel fractionAntiwear additive 0.03 0.03 0.03 — 0.03 0.1 0.005 0.03 0.03 0.03Tert-butyl cumyl — 0.2 0.5 0.5 — — — — — — peroxide Isobutyl cumyl — — —— 0.2 0.2 — — — — peroxide — — — — — — 0.01 0.2 0.5 — 2-ethylhexylnitrate — — — — — — — — — 0.2 Parameter Parameter value Lubricity: the398 356 328 559 359 332 425 346 325 405 corrected parameter of the wearscar diameter at 60° C., μm Cetane number, 46.2 52.0 54.6 54.6 53.3 53.351.4 54.6 57.2 53.2 in 

  Content of adsorption — 692 785 

  698 805 867 769 785 803 744 resine, mg per 150 cm² of the fuel Overallresidue mass, — 0.305 0.400 0.375 0.675 0.725 0.725 0.700 0.675 0.750ml/106 ml ²⁾ Requirements of GOST 32511- 2013, GOST R Content of thecomponents, wt. %/number of sample/ 52368-2005 and Component 6 7 8 8a 910 TR CU 013/2011 Hydroprocessed diesel fraction Hydrocracking 99.9799.77 99.77 99.7 99.77 99.77 diesel fraction Antiwear additive 0.03 0.030.03 0.1 0.03 0.03 Tert-butyl cumyl — 0.2 — — — — peroxide Isobutylcumyl — — 0.2 0.2 — — peroxide — — — — 0.2 — 2-ethylhexyl nitrate — — —— — 0.2 Parameter Parameter value Lubricity: the 404 418 354 337 380 467not more than 460 corrected parameter of the wear scar diameter at 60°C., μm Cetane number, 55.7 64.7 62.2 62.2 63.2 62.2 not less than 51 in 

  Content of adsorption — 133 263 328 236 120 not more than 2500 ¹⁾resine, mg per 150 cm² of the fuel Overall residue mass, — 0.450 0.5500.630 0.575 0.625 not more than 2 ml/106 ml ²⁾ Note: ¹⁾ Determinedaccording to STO 11605031-056, the regulation is established within theMCO (MKO), ²⁾ Determined according to STO 11605031-077-2013, the methodis qualified, it is not included into the ND for diesel fuel

indicates data missing or illegible when filed

TABLE 4 Content of the components, wt. %/number of sample/ Component 11a 2 2a 2b 2c 2d 3 3a 3b 3c Hydroprocessed 99.97 99.77 99.77 98.87 99.599.07 99.77 99.77 99.7 99.4  98.2  diesel fraction Hydrocracking dieselfraction Antiwear additive 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.30.1 0.3 Isopropyl cumyl — 0.2 — — — — — — — — — peroxide Ethyl cumyl — —— — — 0.3 0.2 — — — — peroxide Methyl cumyl — — — — — — — — — 0.3 0.3peroxide 2-ethylhexyl — — — — — — — — — — — acetate 

  Parameter Parameter value Lubricity: the 398 372 356 328 328 

  382 363 350 323 262    354    corrected parameter of the wear scardiameter at 60° C., μm Cetane number, 46.2 35.5 52.9 34.6 34.6 58.6 35.335.3 35.3 33.5  33.1  in 

  Content of — 708 602 705 695 732 728 800 867 832    836    adsorptionresine, mg per 150 cm² of the fuel Overall residue — 0.350 0.300 0.4000.375 0.425 0.400 0.635 0.720  0.625  0.700 mass, ml/106 ml ²⁾Requirements of GOST 32511- Content of the components, wt. %/number ofsample/ 2013, GOST R 52368-2005 and Component 4 4a 4b 4c 5 9 10 TR CU013/2011 Hydroprocessed 98.77 99.77 99.87 99.49 99.77 — — dieselfraction Hydrocracking — — — — — 99.77 99.77 diesel fraction Antiwearadditive 0.005 0.03 0.03 0.03 0.03 0.03 0.03 Isopropyl cumyl — — — 0.5 —— — peroxide Ethyl cumyl — — — — — — — peroxide Methyl cumyl — — — — — —— peroxide 2-ethylhexyl — — — — 0.2 — 0.2 acetate 

  Parameter Parameter value Lubricity: the 425 336 325 353 405 380 407not more corrected than 460 parameter of the wear scar diameter at 60°C., μm Cetane number, 11.4 34.0 57.2 56.3 87.1 

  63.3 83.2 not less than 51 in 

  Content of 749 785 805 792 346 256 110 not more than adsorption 2500¹⁾ resine, mg per 150 cm² of the fuel Overall residue 0.725 0.700 0.6750.725 0.750 0.525 

  0.623 

  not more than 2 mass, ml/106 ml ²⁾ Note: ¹⁾ Determined according toSTO 11605031-056, the regulation is established within the MCO (MKO), ²⁾Determined according to STO 11605031-077-2013, the method is qualified,it is not included into the ND for diesel fuel

indicates data missing or illegible when filed

What is claimed is:
 1. A fuel composition based on a diesel fractionhaving a sulfur content of less than 10 mg/kg with boiling points in therange of 180-360° C., comprising as ignition promoters organic peroxidesselected from a group of: di-tert-butyl peroxide, 1,1-di(tert-butylperoxy)cyclohexane, dicumyl peroxide, and an antiwear additive based oncarboxylic acids having the following ratio of components, wt. %:organic peroxide from 0.01 to 0.5; antiwear additive from 0.005 to 0.1;and diesel fraction up to
 100. 2. A fuel composition based on a dieselfraction having a sulfur content of less than 10 mg/kg with boilingpoints in the range of 180-360° C., comprising as ignition promotersorganic peroxides selected from a group of: tert-butyl cumyl peroxide,isobutyl cumyl peroxide, n-butyl cumyl peroxide, and an antiwearadditive based on carboxylic acids having the following ratio ofcomponents, wt. %: organic peroxide from 0.01 to 0.5; antiwear additivefrom 0.005 to 0.1; and diesel fraction up to 100.